AP Chemistry Predicting Products Tutorial
Answers to COMPLEX IONS #13-24
13. Dilute hydrochloric acid is added to a solution of diammine silver(I) nitrate.
2H+ + [Ag(NH3)2]+  Ag+ + 2NH4+
14. A suspension of copper(II) hydroxide is treated with an excess of ammonia water.
Cu(OH)2 + 4NH3  [Cu(NH3)4]2+ + 2OH15. A solution of diammine silver(I) chloride is treated with dilute nitric acid.
2H+ + [Ag(NH3)2]+  Ag+ + 2NH4+
16. An excess of concentrated ammonia solution is added to freshly precipitated copper(II) hydroxide.
Cu(OH)2 + 4NH3  [Cu(NH3)4]2+ + 2OH17. Excess concentrated potassium hydroxide solution is added to a precipitate of zinc hydroxide.
2OH- + Zn(OH)2  [Zn(OH)4]218. Excess concentrated sodium hydroxide solution is added to solid aluminum. (see#2)
6OH- + Al  [Al(OH)6]3Note: The complex ion really formed is [Al(OH)4]-. The rule of thumb is double the charge for
the number of ligands, but I want to point out there are exceptions as in this case. The
graders of the ap test know you will use the rule of thumb, so if you put [Al(OH) 6]3- you will get
full credit. If you put the real answer you will look good .
19. A concentrated solution of ammonia is added to a solution of copper(II) chloride.
4NH3 + Cu2+  [Cu(NH3)4]2+
20. A solution of ammonium thiocyanate is added to a solution of iron(III) chloride.
6SCN- + Fe3+  [Fe(SCN)6]321. Solid aluminum oxide to excess sodium hydroxide.
Al2O3 + 12OH-  2[Al(OH)6]3- (OR [Al(OH)4]-]) + 3O222. Excess concentrated ammonia added to solution of barium hydroxide.
NH3 + Ba2+ + OH-  NO RXN
Note: Ba2+ is not a transition metal, so this cannot form a complex ion. This was an accidental
question, because you will never see a reaction on the AP exam that has no reaction.
23. An excess of nitric acid solution is added to a solution of tetraaminecopper(II) sulfate.
4H+ + [Cu(NH3)4]2+  Cu2+ + 4NH4+
24. Excess concentrated ammonia solution is added to a suspension of silver chloride.
2NH3 + AgCl  [Ag(NH3)2]+ + Cl-